Allen Neuner and his partner, Bill Stella, share a home in Somerville. They share expenses. They also share, as Neuner put it, "our lives with each other."

But with New Jersey among the 45 states that do not recognize same-sex marriage, the two have never been able to legally identify themselves as a married couple. Now, for the first time, they will have the opportunity to call their union a marriage in an official government document.

In a policy shift experts say could radically reshape demographic profiles of the gay community, the U.S. Census this year will let same-sex couples label themselves as husband or wife even if their relationships are not recognized by law.

"Right now, we’re as married as a couple can be, so I’m not going to have any trouble checking the husband box," said Neuner, 58, an event planner who has been with his partner for a decade.

Neuner is among those hailing the change, which will appear on Census forms due to be mailed out next week. The forms do not explicitly recognize civil unions, which are legal in New Jersey. Instead, the documents offer one of two boxes for same-sex couples — "husband or wife" or "unmarried partners."

The census bureau plans to leave it to responders to characterize their own relationships.

"We have a policy of self-identification," said Igor Alves, a media specialist with the agency. "If they want to put husband or unmarried partner, that is up to them. We basically want to tally what they select."

The new policy took effect last summer, when the Commerce Department released a legal opinion that argued the federal government could tabulate and release same-sex marriage data under the 1996 Defense of Marriage Act.

In the last decennial count, officials re-coded same-sex husband or wife answers to "unmarried partners," since no state in the country recognized same-sex marriage at the time.

Since then, the legal landscape has changed. Five states — Iowa, Connecticut, Vermont, Massachusetts and New Hampshire — and the District of Columbia now allow gay couples to legally marry, leaving census tabulators in a new bind.

"The truth is that the number of kinds of legally married couples in this country is a very complicated situation," said Gary Gates, a demographer with the University of California, Los Angeles. "How do you keep up with that?"

Despite the form’s inflexibility, Gates believes the census effort will offer a rich source of data about how same-sex couples describe themselves, as well as their family structure.

The Census will release a special report about its data on same-sex couples next year, Alves said.

The new numbers could drastically affect political debates on gay issues, said Steven Goldstein, chairman of the gay-rights group Garden State Equality.

"Politicians use the Census as a yardstick for a community’s power," he said. "That in turn affects the enactment of public policies."

Staff writer Mark Mueller and the Associated Press contributed to this report.

Excerpts from New Jersey state Senate debate on same-sex marriageNew Jersey state senators voted 20 to 14 to defeat a bill that would legalize same-sex marriage. Gay rights activists had hoped to get the bill passed in the lame duck session because Gov. Jon Corzine has said he would sign the bill. Governor-elect Chris Christie has said he would veto the bill. (Video by Nyier Abdou/The Star-Ledger)